Underreamer.



W. WAGNER.

UNDERREAMER.

APPLICATION FILED APR. 23. 1.913. RENEWED APR. 24. I915.

1 1493999 Patented Aug. 10, 1915.

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W. WAGNER.

UNDERREAMER.

APPLICATION FILED APR 2 1913 E WED APR 24.

Patented Aug. 10, 1915.

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, To all whom it may concern:

WARREN WAGNER, OE BURKBlIBNETT, TEXAS.

I INDE REAMEB.

Specification of Letters Patent.

Patented Aug. 10, 1915.

Application filed April 23, 1913, Serialflo. 763,164. Renewed April 24,'1915. Serial No. 23,769.

Be it known that I, WARREN WAGNER, citizen of the United States,residing at Burkburnett, inthe county of Wichita and State of Texas,have invented certain new and useful Improvements in Underreamers, ofwhich the following is a specification, reference being had to theaccompanying drawings. I

This invention relates to improvements in underreamers such as areemployed for reaming wells beneath the lower end of a tube or casing,the invention having for its primary object to increase the durability,efliciency and general serviceability of the underreamer disclosed in myPatent Number, 1,080,666, issued December 9, 1918.

Another object of the invention resides in the provision of improvedmeans for seating the bits or cutterswhen in their operative' positionsagainst the bottom of the mandrel, whereby separation or spreading ofthe bits is rendered impossible and a very rigid and durable structureobtained.

The invention further resides in the improved form and construction ofthe cutting bits, and means for connecting the same to the springpressed plunger or stem mounted within the mandrel or body of the tool.

iVith the above and other objects in view as will become apparent as thedescription proceeds, the invention consists in certain constructions,combinations and arrangements of the parts that I shall hereinafterfully describe and claim.

For a full understanding of the invention, reference is to be had to thefollowing desoription and accompanying drawings, in which- Figure 1 is aside elevation of an underi'earner embodying the present invention; Fig.2 is a view looking at right angles to Fig. 1 showing the positions ofthe cutting bits as the same are being lowered into the well casing.Fig. 3 is a longitudinal section; Fig. 4 is a section taken on the line44 of Fig. 3; Fig. 5 is a bottom plan view of the body of the mandrel;Fig. 6 is a detail perspective view ,of one of the cutting bits againstthe lower end of the mandrel.

slot 9 connects these channels with the bore of the mandrel. The lowerend of this slot 1s widened or flared as indicated at 10 and the opposedwalls of the channels are provided with longitudinal grooves 11. Theinner wallsv of these grooves are inwardly inchned as shown at 12,whereby the grooves are widened at their lower open ends. Incllnednotches or recesses 13 open into the guide grooves 11 at the upper endsof the inclined walls 12 thereof. The lower end of the stock or mandrelis provided with a central longitudinally extended web 14, the lower endof which is beveled in opposite directions as indicated at 15. Upon eachside of this web, and at opposite sides of the channels 8, the lower endof the mandrel is formed with the lugs 16, the inner faces of which areobliquely inclined or beveledas at 17. From the upper ends of theseinclined faces, the lower surface of the mandrel 1s curved or convex tothe point of its juncture with the web 14 as shown. at 18. The purposeof this particular construction of the mandrel will be more fullyreferred to m the following description.

The cutting bits illustrated in detail in i Fig. 6 each consists of thebit blade or body 19 which has formed upon one of its ends alongitudinally extended rectangular shank 20. The outer face of the bitbody is convex and is slightly inclined outwardly with relation to thelongitudinal axis of the shank. The lower end faces of the 'bit bladesare transversely inclined and are slightly concaved as 'shown at 21;while the inner faces of said blades are inclined as shown at 22, saidinclined faces diverging from the web 14 on the lower end of the mandrelwhen the bits are mounted therein. Said inclined faces of the bitsterminate at one of their ends at a point adjacent the upper end of thebit body, from which point, the inner faces of the bits arelongitudinally extended as at 23 for'engagement with the web 14. Theupper end of the body of each bit upon opposite sides of the shank 20 isprovided with an abutm nt lug 24 having a beveled or inclined face 25for engagementwith the beveled face 17 on one of the lugs 16 formed uponthe mandrel. Each lug 24 is also provided with a curved 'or concave face26 to engage the convex faces 18 of the mandrel 5, It will thus beapparent that when the bits are in their cutting positions, as shown inFig. 1, the lugs 16 against which the abutment lugs 24 on the cuttingbits engage will effectually prevent relative lateralspreading movementof the cutting bits.

Upon the opposite faces of each of the bit shanks 20, the longitudinallyextending ribs 27 are formed and these ribs are adapted to be receivedin the grooves 11 provided in the opposed walls of the channels 8. Uponthe end of the shank 20 and projecting from its opposite faces, 'thesemi-cylindrical lugs 28 are formed which are also adapted for movementin the grooves 11. Theselugs are .adapted to be passed through thenotches or recesses 13 when the bits are fitted in the mandrel and whenin position, the plane faces of the lugs are opposed to said recesses.As the upper and lower walls of these recesses are beveled or inclined,all liability of-the lugs 28 movin outwardly through said recesses whenthe its are extended, for

the insertion of the tool in the well tube,

is obviated.

29 indicates the spring pressed stem or plunger whichis arranged in thebore 6 of the mandrel or stock, and 30 designates the spring arrangedthereon. One end of this spring engages the head 31 on theupper end ofthe stem while the other end of said spring bears against the lower endwall of the enlarged portion ofthe bore 6. This stem is provided in its"lower end with an opening 32 and each of the bit shanks 20 is alsoprovided in its upper end with a rectangular opening 33, the opening inone shank, however, being. somewhat larger than the opening in the othershank. A

34 designates the pin or key which tapers inwidth longitudinally. Thiskey is centrally provided upon one of its longitudinal edges with alugor extension 35 which is adapted to "be received in the opening 32provided in the spring pressed stem or plunger'. The lug 35 on the keyeffectually pre- 1 vents longitudinal movement of said key in eitherdirection through the openings 33 in the cutting bits, thus eliminatingall liability of disconnection of said-bits from the plunger 29'. It isof course understood that the larger opening 33 is equivalentin depth tothe-width of the central portion of the key whereon the lug.35 is formedso that saidkey may .bereadily insertedthrough said latter opening andthe lug 3.5 engaged in the opening 32 of the plunger. The bit having thelarger key receivingopening'33 is provided with a pm 39 extendingtransversely other.

-is permitted by the provision of the inclined of said opening, said pinacting as a wedge for the key 34 to prevent the same from working loose.a

The web 14 formed on the lower end of the mandrel or stock is providedwith a central longitudinally extending opening 36 in which a rod 37 isloosely disposed. The upbits moving inwardly beneath the lower edge ofthe web 14 into engagement with each This inward movement 'of the bitsinner walls 12 ;of the grooves 11, the inner faces of the bit shanks 20being inclined as indicated at 20'. It will be understood that the ribs27 of the cuttingbits fit loosely in the'slo'ts 11 '0f the 'mandrel, andin'view of the tapering form of the key 34, one of the bits'will shiftslightlylongitudinally upon the end of the key, while the other rocksupon the pin 39 as the bits are forced inwardly toward each other. Afterdisposing the bits in this manner they are inserted into the well tubingand forced downwardly therein, the upward pull upon said bits ex- .ertedby the spring 30 tending to move the channels 8,-the' body portions ofthe cutting bits outwardly into frictional engagemeht with the wellcasing; Each of the bit shanks is further provided upon its outer facewith a shoulder 20, and these shoulders are adapted for engagement withthe lower edge of the well tube when the bits are disposed beneath thesame in their operative positions as shown'in Fig. 3, the spring 30acting to force the stem 29 upwardly in the mandrel and thereby throwthe body portions of'the ,bits outwardly upon opposite sides of the web14 and into engagement with the walls of the well. When the reanier isrotated, in

the ordinary manner, the walls will be reamed or cut away beneath thelower end of the casing or tube.

In Fig. 8 of the drawings, I have shown a slightly modified form of thecuttin bits wherein the same are provided with longi tudinal inner faces21' at the upper ends of which the inclined shoulders .22 are formed.Beyond these shoulders, the bits are provided with plane faces extendingthe entire width of the body portions of the bits for engagement withthe web 14. It will be understood that the inclined shoulders 22' en-.

'gage the beveled surfaces-15 on the lower edge of said web. In thisform-of the bit,

In Fig. 9, I have illustrated a slightly modified manner of seating thecutting bits against the bottom face of the mandrel when the same are intheir operative positions. In

this construction the mandrel is provided upon opposite sides of itscentral depending web and on each side of the bit receiving channelswith oppositely inclined faces 41 to receive the correspondinglyinclined upper faces 42 which are provided upon the body portions of thecutting bits. It will thus be seen that a bearing face of comparativelyextensive area is provided for the, cutting bits so that the same aregreatly strengthened and braced during their cutting action.

From the foregoing, it will be seen that I have greatly improved theconstruction of the underreamer as shown in my prior application forpatent hereinbefore referred to, and materially increased its operatingefliciency and durability, the bits being seated against the lower endof the mandrel in such manner as to cause the same when subjected tolongitudinal pressure to bear against the convex faces 18 of the mandrelwhich tends to force the bits upwardly and outwardly, thereby relievingthe inner faces of the bits which engage the Web 14, of undue friction,and maintaining a smooth bearing surface for the bits. When the reamingoperation is completed, the reamer may be readily withdrawn by simplypulling upwardly upon the same. The shoulders 20" of the cutting bitsengaging the lower end of the well tubing holds the bits while themandrel moves upwardly within the lower end of the tube. When the loweredge of the depending flange or web 14 reaches the point of juncture ofthe shanks with the body portions of the cutting bits, the beveled orinclined faces 20' of said shanks move inwardly against the oppositesides of said web thus permitting the cutting bits to be drawn upwardlywithin the lower end of the well tube.

The device as a whole is comparatively simple in construction and thevarious parts thereof may be easily and quickly assembled ordisassembled when it is necessary to sharpen the cutting bits.

It will be seen that I have made no material additions to theconstruction of my invention as shown in the prior application and itwill therefore be appreciated that the improved device may bemanufactured with practically no increase-in cost.

While I have shown and described the preferred form and construction ofthe several elements employed, it will be obvious that the same aresusceptible of considerable modification in the form, proportion andarrangement thereof without de arting from the essential features orsacr' cing any of the advantages of the invention.

Having thus described the invention, what is claimed is: y

In an underreamer, a mandrel, opposed cutting bits longitudinallymovable in the mandrel, and fastened 'to said mandrel by bayonet slotstherein and lugs on said bits, each of said bits having a portionprojecting beyond the periphery of the mandrel, a spring pressed stemmounted in the mandrel and provided with a rectangular opening, each ofsaid bits also having a rectangular opening, a key insertible throughthe openings in the cutting bits and said stem, and means removablymounted in the projection on one bit .to positively lock the key againstlongitudinal movement through said openings, said means being removablefrom the bit while the same is in its normal position in the mandrel.

In testimony whereof I hereunto aflix my signature in the resence of twowitnesses.

- WABREN -WAGNER.

Witnesses:-

M. C. LYDDANE, E. L. WHITE.

